The invention relates to the continuous tape assembly of semiconductor devices. Such tapes are either metallic or composite metal insulator film structures. In either case the tape includes a succession of metal finger patterns that have an inner terminal form that mates with the bonding pad pattern on the semiconductor device. My U.S. Pat. No. 4,000,842 details the thermocompression (TC) bonding of copper fingers to a gold structure on a semiconductor device. My U.S. Pat. No. 4,188,438 covers the use of anti-oxidants on copper that is to be TC bonded. My copending patent application Ser. No. 921,642 was filed July 3, 1978 and relates to the use of bumps on the copper tape fingers to provide improved TC bonding without forming bumps on the semiconductor device. My patent application Ser. No. 58,404 was filed July 17, 1979, and relates to a process and machine for producing laminated tape. This is a continuation-in-part of patent application Ser. No. 921,644 which was filed July 3, 1978, and is now abandoned. My copending application Ser. No. 138,030 filed Apr. 7, 1980 titled "LEAD DESIGN FOR SEMICONDUCTOR AUTOMATIC ASSEMBLY TAPE" shows an improved finger structure and its teaching is incorporated herein by reference.
In the assembly process after the semiconductor device is bonded to the tape, the fingers are excised from the tape and bonded to the lead frame. This is done in a high speed thermocompression gang bonder machine. One of the problems encountered in this machine results from displaced fingers which can clog the machine and therefore slow its throughput.
If even one finger is displaced, the machine can become clogged and require shutdown for maintenance. Since the machine runs at a high speed, any downtime can result in substantial loss of production. Thus, it is clear that a very reliable bonding technique must be employed along with some means for immobilizing the fingers.
One useful means for avoiding finger displacement is shown in my U.S. Pat. No. 4,063,993, which discloses the use of insulating rings deposited on the metal stock from which the fingers are constructed. In my U.S. Pat. No. 4,099,660, a plastic film is used to hold the fingers in position while the fingers are formed by translating the chip that is bonded thereto. Both of these approaches involve composite tape materials.